# What is 89 factorial ?

Steps to calculate factorial of 89

## How to calculate the factorial of 89

To find 89 factorial, or 89!, simply use the formula that multiplies the number 89 by all positive whole numbers less than it.

Let's look at how to calculate the Factorial of Eighty-nine :

89! is exactly : 16507955160908461081216919262453619309839666236496541854913520707833171034378509739399912570787600662729080382999756800000000000000000000

Factorial of 89 can be calculated as:
89! = 89 x 88 x 87 x 86 x ... x 3 x 2 x 1

The number of trailing zeros in 89! is 21

The number of digits in 89 factorial is 137.

## What Is Factorial?

A factorial is displayed by an integer and an exclamation mark. In arithmetic, factorial is a multiplication process of natural numbers .

It multiplies the number by every noreal number that is less than it .

Symbolically, it is showed as "!".

The function is used, among other things, to find the "n" way objects can be structured .

## Factorial Formula

To find the factorial of any given number, change the exact value for n in the given equation :

n! = n × (n-1) × (n-2) × (n-3) × ….× 3 × 2 × 1

The expansion of the formula provides the numbers to be multiplied at the same time to obtain the factorial of the number.

We can also determine a factorial from the prior one. The factorial of any number is that number times the factorial of (that number minus 1).

So the rule is : n! = n × (n−1)!

Example :
89! Factorial = 89 x 88 x 87 x 86 x ... x 3 x 2 x 1 = 89 × 88! = 16507955160908461081216919262453619309839666236496541854913520707833171034378509739399912570787600662729080382999756800000000000000000000

## What are Factorials Used For?

The best use of factorial is in Combinations and Permutations.

Example : Determine how to arrange letters without repeating?

There one way for 1 letter "a":
2 ways for two letters "ab": ab, ba.
There are 6 ways for 3 letters "abc": abc acb cab bac bca.
There are 24 ways for 1234 of the letters "abcd"

## Frequently Asked Questions on Factorial

### Can we have factorials for negative numbers ?

Negative number factorials are undefined

### What Is 0!

Zero factorial or Factorial of 0 is simple, and its value is corresponding to 1. So, 0! = 1.